Conventional industrial grinding machines used for rubber recycling and other grinding purposes are large and cumbersome, have low output volume and use excessive energy. Currently used "cracker mill" machines use two rollers operating side-by-side with minimal clearance between them, one rolling at a faster speed than the other, either by adjusting the revolutions per minute or by using rollers of differing diameters. The friction caused by the difference in speed causes the rubber or other material to break. Yet other machines use blades with knife edges to cut the material into small pieces.